Tribology 1 – Lubrication

The Tribology Group of the University of Pisa is involved in many theoretical and experimental researches on piezo-elastofluidodynamic, fluidodynamic and fluidostatic lubrication. Typical industrial applications are lubricated contacts in gears, cams, roller and ball bearings.

The TriboLab is equipped with two test rigs specifically designed for investigating the above mentioned contacts. They are able to simultaneously measure the friction force, the film thickness and its shape.

The apparatus for investigations on non-conformal contacts, as cam-follower and gear teeth, is shown in Fig.1. The contact force can be completely estimated thanks to a system of nine annular load cells. The film thickness and shape are measured by optical interferometry. Interference images are recorded by a high-speed camera connected to a microscope and analysed by purposely developed programs. An example of interference image of a ball-plane contact is shown in Fig.2.

Fig.1 – Photographs showing a global view and a detail of the cam-follower test rig.
Fig.2 – Lubricated ball-plane contact and film shape reconstruction.

Research group
Enrico Ciulli, Francesca Di Puccio, Lorenza Mattei

External collaborations:
AC2T research GmbH ( www.ac2t.at)


Funding:

PRIN 2007 “Non-conformal pairs of vehicles”

Main publications:

  • L. Mattei, F. Di Puccio, B. Piccigallo, E. Ciulli, “Lubrication and wear modelling of artificial hip joints: A review”, Tribology International, Volume 44, Issue 5, May 2011, Pages 532-549, DOI: 10.1016/j.triboint.2010.06.010
  • E. Ciulli, F. Fazzolari, B Piccigallo, “Experimental study on circular eccentric cam–follower pairs“, Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, Vol.228(10), 2014. p.1088-1098. doi:10.1177/1350650114529943
  • G. Pugliese, E. Ciulli and F, Fazzolari, “Experimental aspects of a cam-follower contact“, in T. Uhl (ed.), Advances in Mechanism and Machine Science, Mechanisms and Machine Science 73, Springer Nature Switzerland AG 2019, pp 3815-3824. https://doi.org/10.1007/978-3-030-20131-9_378